Answer

$\sin1800^{\circ}=0$

Work Step by Step

1. What we know about 1800 degree angle
$\theta=0^{\circ}$ (because it is a co-terminal angle and values of x and y will be the same)
$x=1$
$y=0$
$r=1$
2. Substitute in:
$\sin\theta=\frac{y}{r}=\frac{0}{1}=0$